The Organic Light Emitting Display (OLED) possesses many outstanding properties of self-illumination, low driving voltage, high luminescence efficiency, short response time, high clarity and contrast, near 180 degree view angle, wide range of working temperature, applicability of flexible display and large scale full color display. The OLED is considered as the most potential display panel.
The OLED display element generally comprises a substrate, an anode located on the substrate, a hole injection layer located on the anode, a hole transporting layer located on the hole injection layer, an emitting layer located on the hole transporting layer, an electron transporting layer located on the emitting layer, an electron injection layer located on the electron transporting layer and a cathode located on the electron injection layer. The principle of the OLED element is that the illumination generates due to the carrier injection and recombination under the electric field driving of the semiconductor material and the organic semiconductor illuminating material. Specifically, the ITO pixel electrode and the metal electrode are respectively employed as the anode and the cathode of the OLED element. Under certain voltage driving, the electron and the hole are respectively injected into the electron and hole transporting layers from the cathode and the anode. The electron and the hole respectively migrate from the electron and hole transporting layers to the emitting layer and bump into each other in the emitting layer to form an exciton to excite the emitting molecule. The latter can illuminate after the radiative relaxation.
In the Active Matrix (AM) organic light emitting diode display device, the Thin film transistor (TFT) controlling the OLED element is commonly manufactured at the side of the anode, which requires that the TFT has to be p type. The n type mobility of the regular amorphous silicon TFT and the polysilicon TFT is obviously larger than the p type mobility. The utilization of the inverted OLED element structure can make the n type thin film transistor of excellent performance be applied in the pixel circuit of the AMOLED display device to have more options for the driving circuit design of the AMOLED display device.
In the Active Matrix (AM) organic light emitting diode display device, the Thin film transistor (TFT) controlling the OLED element is commonly manufactured at the side of the anode, which requires that the TFT has to be p type. The n type mobility of the regular amorphous silicon TFT and the polysilicon TFT is obviously larger than the p type mobility. The method is to drop the function material ink into the predetermined pixel areas with a plurality of nozzles. Then, the required pattern is formed after the solvent is evaporated.
The metal nanoparticles provide many excellent optical and electrical properties with their special volume effect, quantum size effect, surface effect and macroscopic quantum tunneling effect.